runtime: wrap nanotime, walltime, and write

In preparation for general faketime support, this renames the existing
nanotime, walltime, and write functions to nanotime1, walltime1, and
write1 and wraps them with trivial Go functions. This will let us
inject different implementations on all platforms when faketime is
enabled.

Updates #30439.

Change-Id: Ice5ccc513a32a6d89ea051638676d3ee05b00418
Reviewed-on: https://go-review.googlesource.com/c/go/+/192738
Run-TryBot: Austin Clements <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: aclements

misc/wasm/wasm_exec.js

@@ -248,13 +248,13 @@
 						this.mem = new DataView(this._inst.exports.mem.buffer);
 					},
 
-					// func nanotime() int64
-					"runtime.nanotime": (sp) => {
+					// func nanotime1() int64
+					"runtime.nanotime1": (sp) => {
 						setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
 					},
 
-					// func walltime() (sec int64, nsec int32)
-					"runtime.walltime": (sp) => {
+					// func walltime1() (sec int64, nsec int32)
+					"runtime.walltime1": (sp) => {
 						const msec = (new Date).getTime();
 						setInt64(sp + 8, msec / 1000);
 						this.mem.setInt32(sp + 16, (msec % 1000) * 1000000, true);

src/runtime/os2_aix.go

@@ -390,10 +390,10 @@ func exit(code int32) {
 	exit1(code)
 }
 
-func write1(fd, p uintptr, n int32) int32
+func write2(fd, p uintptr, n int32) int32
 
 //go:nosplit
-func write(fd uintptr, p unsafe.Pointer, n int32) int32 {
+func write1(fd uintptr, p unsafe.Pointer, n int32) int32 {
 	_g_ := getg()
 
 	// Check the validity of g because without a g during
@@ -402,7 +402,7 @@ func write(fd uintptr, p unsafe.Pointer, n int32) int32 {
 		r, _ := syscall3(&libc_write, uintptr(fd), uintptr(p), uintptr(n))
 		return int32(r)
 	}
-	return write1(fd, uintptr(p), n)
+	return write2(fd, uintptr(p), n)
 
 }
 

src/runtime/os3_solaris.go

@@ -393,11 +393,11 @@ func munmap(addr unsafe.Pointer, n uintptr) {
 	sysvicall2(&libc_munmap, uintptr(addr), uintptr(n))
 }
 
-func nanotime1()
+func nanotime2()
 
 //go:nosplit
-func nanotime() int64 {
-	return int64(sysvicall0((*libcFunc)(unsafe.Pointer(funcPC(nanotime1)))))
+func nanotime1() int64 {
+	return int64(sysvicall0((*libcFunc)(unsafe.Pointer(funcPC(nanotime2)))))
 }
 
 //go:nosplit
@@ -499,7 +499,7 @@ func usleep(µs uint32) {
 }
 
 //go:nosplit
-func write(fd uintptr, buf unsafe.Pointer, nbyte int32) int32 {
+func write1(fd uintptr, buf unsafe.Pointer, nbyte int32) int32 {
 	return int32(sysvicall3(&libc_write, uintptr(fd), uintptr(buf), uintptr(nbyte)))
 }
 

src/runtime/os_aix.go

@@ -323,15 +323,15 @@ const (
 )
 
 //go:nosplit
-func nanotime() int64 {
+func nanotime1() int64 {
 	tp := &timespec{}
 	if clock_gettime(_CLOCK_REALTIME, tp) != 0 {
 		throw("syscall clock_gettime failed")
 	}
 	return tp.tv_sec*1000000000 + tp.tv_nsec
 }
 
-func walltime() (sec int64, nsec int32) {
+func walltime1() (sec int64, nsec int32) {
 	ts := &timespec{}
 	if clock_gettime(_CLOCK_REALTIME, ts) != 0 {
 		throw("syscall clock_gettime failed")

src/runtime/os_js.go

@@ -12,7 +12,7 @@ import (
 
 func exit(code int32)
 
-func write(fd uintptr, p unsafe.Pointer, n int32) int32 {
+func write1(fd uintptr, p unsafe.Pointer, n int32) int32 {
 	if fd > 2 {
 		throw("runtime.write to fd > 2 is unsupported")
 	}

src/runtime/os_nacl.go

@@ -300,6 +300,8 @@ var lastfaketime int64
 // but the timestamp must increase if the fd changes.
 var lastfaketimefd int32
 
+func walltime() (sec int64, nsec int32)
+
 /*
 An attempt at IRT. Doesn't work. See end of sys_nacl_amd64.s.
 

src/runtime/os_plan9.go

@@ -328,7 +328,7 @@ func usleep(µs uint32) {
 }
 
 //go:nosplit
-func nanotime() int64 {
+func nanotime1() int64 {
 	var scratch int64
 	ns := nsec(&scratch)
 	// TODO(aram): remove hack after I fix _nsec in the pc64 kernel.
@@ -373,7 +373,7 @@ func postnote(pid uint64, msg []byte) int {
 		return -1
 	}
 	len := findnull(&msg[0])
-	if write(uintptr(fd), unsafe.Pointer(&msg[0]), int32(len)) != int64(len) {
+	if write1(uintptr(fd), unsafe.Pointer(&msg[0]), int32(len)) != int32(len) {
 		closefd(fd)
 		return -1
 	}
@@ -451,8 +451,8 @@ func read(fd int32, buf unsafe.Pointer, n int32) int32 {
 }
 
 //go:nosplit
-func write(fd uintptr, buf unsafe.Pointer, n int32) int64 {
-	return int64(pwrite(int32(fd), buf, n, -1))
+func write1(fd uintptr, buf unsafe.Pointer, n int32) int32 {
+	return pwrite(int32(fd), buf, n, -1)
 }
 
 var _badsignal = []byte("runtime: signal received on thread not created by Go.\n")

src/runtime/os_windows.go

@@ -416,8 +416,6 @@ func osinit() {
 	stdcall2(_SetProcessPriorityBoost, currentProcess, 1)
 }
 
-func nanotime() int64
-
 // useQPCTime controls whether time.now and nanotime use QueryPerformanceCounter.
 // This is only set to 1 when running under Wine.
 var useQPCTime uint8
@@ -542,8 +540,12 @@ func exit(code int32) {
 	stdcall1(_ExitProcess, uintptr(code))
 }
 
+// write1 must be nosplit because it's used as a last resort in
+// functions like badmorestackg0. In such cases, we'll always take the
+// ASCII path.
+//
 //go:nosplit
-func write(fd uintptr, buf unsafe.Pointer, n int32) int32 {
+func write1(fd uintptr, buf unsafe.Pointer, n int32) int32 {
 	const (
 		_STD_OUTPUT_HANDLE = ^uintptr(10) // -11
 		_STD_ERROR_HANDLE  = ^uintptr(11) // -12
@@ -640,6 +642,9 @@ func writeConsoleUTF16(handle uintptr, b []uint16) {
 	return
 }
 
+// walltime1 isn't implemented on Windows, but will never be called.
+func walltime1() (sec int64, nsec int32)
+
 //go:nosplit
 func semasleep(ns int64) int32 {
 	const (

src/runtime/stubs2.go

@@ -21,7 +21,7 @@ func exit(code int32)
 func usleep(usec uint32)
 
 //go:noescape
-func write(fd uintptr, p unsafe.Pointer, n int32) int32
+func write1(fd uintptr, p unsafe.Pointer, n int32) int32
 
 //go:noescape
 func open(name *byte, mode, perm int32) int32

src/runtime/stubs3.go

@@ -4,12 +4,11 @@
 
 // +build !plan9
 // +build !solaris
-// +build !windows
 // +build !nacl
 // +build !freebsd
 // +build !darwin
 // +build !aix
 
 package runtime
 
-func nanotime() int64
+func nanotime1() int64